Field of the Invention
The present invention relates to drinking containers for liquids. More particularly, the present invention is directed to drinking containers and lids for drinking containers that are openable by the user's lips.
Lip-openable containers are known. Such containers are desirable for children in their progression from use of a container whose lid has a spout, to an adult open-ended drinking container. Lip-openable containers are desirable because, as compared to containers with a spout, they do not require orientation of the cup to bring a spout to the children's lips, and they help children learn the sipping action needed for use of an open-ended container, such as a glass. Also, lip-openable containers are highly convenient since only one hand is required to drink from the container, and when drinking is completed the container closes automatically.
Heretofore, lip-openable containers have employed a movable lid seated within a central opening of the container closure cap. The lid functions as a valve. In its normal position, the lid is urged or biased upward by an underlying spring device, so that the periphery of the lid seats against an overlying, surrounding valve seat that is part of the closure cap. To drink from the container, a person uses his or her upper lip to push downward on a portion of the periphery of the lid, against the bias of the spring, to create an opening between the lid and the valve seal that allows liquid to flow therethrough.
Heretofore, the movable lid has been constructed of a rigid material. The application of lip pressure to the rigid lid, for example, at about 9 o'clock on its circumference, would depress the lid from a pivot point seeking a location at about 3 o'clock, i.e., about 180.degree. opposite from where the pressure is applied. This is disadvantageous because with downward pressure of a user's lip that is necessarily exerted in a relatively localized area, a portion of the rigid lid substantially wider than the localized area of pressure, e.g., a segment of an arc approaching 180.degree. or more of the periphery of a circular lid, is removed from the valve seat. This causes spillage at the sides of the user's lips. Also, a rigid lid does not have a natural feel and is uncomfortable to the user's lips.
It would be desirable to have an improved lip-openable container that does not require a spring device. It would also be desirable to have a lip-openable container that does not employ a rigid lid, and that when open, allows liquid flow into the user's mouth and not outside or beyond it. It would thus be desirable to have a non-rigid lid that avoids spillage of liquid from an excessively wide opening, as is created between a rigid lid and its surrounding valve seat when a user applies localized lip pressure to the rigid lid.